Nitrox and gas narcosis

[wedivebc]

So because o2 is not inert (like nitrogen, helium & neon) it according to some theories remains non-narcotic (though toxic)

are there any other "safe" gases for your body that are not inert as well? perhaps some that would be less toxic at depth?

There are no other gasses that are metabolized by your body like O2.

 

[kidspot]

sure would be nice to find a gas that was metabolized, not toxic and non-narcotic...

 

[triton94949]

sure would be nice to find a gas that was metabolized, not toxic and non-narcotic...

100% O2 works like a charm, you just cannot go deeper than 20 ft.

 

[triton94949]

I dive rebreather and I have seen immediate changes in "buzz" when the PO2 drops, depth being constant. Only thing is my experience is opposite yours so I guess the whole thing is very subjective.

Well of course, because if your depth is constant and you just dropped your PO2 than that also means your FO2 dropped as well, and that is only possible if you injected Helium into your mix.

 

[wedivebc]

Well of course, because if your depth is constant and you just dropped your PO2 than that also means your FO2 dropped as well, and that is only possible if you injected Helium into your mix.

No that is not true at all. With a closed circuit rebreather the fraction of O2 is not constant, the PPO2 can be held constant or can be altered by the diver. In a semi closed rebreather the fraction is constant but can vary with workload.

 

[triton94949]

No that is not true at all. With a closed circuit rebreather the fraction of O2 is not constant, the PPO2 can be held constant or can be altered by the diver. In a semi closed rebreather the fraction is constant but can vary with workload.

Are you going to tell us what you offset the FO2 with? More N2? More HE?

 

[wedivebc]

Are you going to tell us what you offset the FO2 with? More N2? More HE?

Sorry I was not very clear. The loop gas is made up of O2 and N2 (air diluent). If I were to stop injecting O2 to replace what my body consumes the PPO2 will eventually drop thereby allowing the PPN2 to increase. The first time I noticed the buzz was doing a SCR bailout drill at 100ft. This involves exhaling through the nose and breathing in diluent every third breath. This causes a rapid drop in PO2 from 1.3 to .84 at 100ft and caused a noticable perception narrowing (at least in my case) due to the increase in PPN2 2.7 - 3.16

 

[triton94949]

Sorry I was not very clear. The loop gas is made up of O2 and N2 (air diluent). If I were to stop injecting O2 to replace what my body consumes the PPO2 will eventually drop thereby allowing the PPN2 to increase. The first time I noticed the buzz was doing a SCR bailout drill at 100ft. This involves exhaling through the nose and breathing in diluent every third breath. This causes a rapid drop in PO2 from 1.3 to .84 at 100ft and caused a noticable perception narrowing (at least in my case) due to the increase in PPN2 2.7 - 3.16

Well that would certainly suggest that N2 is more narcotic than O2.

However it does not go very far in telling us how much more? The two gasses could still be very close to the same in narcotic value, to all intents and purposes, except in the extreme cases that you have triggered.

 

[wedivebc]

Well that would certainly suggest that N2 is more narcotic than O2.

However it does not go very far in telling us how much more? The two gasses could still be very close to the same in narcotic value, to all intents and purposes, except in the extreme cases that you have triggered.

Like I suggested before YMMV and narcotic potential is very difficult to measure, especially when it involves a gas that becomes toxic at levels far below pressures that would make it narcotic. Most people feel narced with a PPN2 of 3.0ata or so. The trouble is to really feel it some of us need 4.5ata or so and I would not be willing to get anywhere near that exposure of O2, even in a dry chamber.

 

[joedelt]

my understaning was that in the typical depths nitrox is used the narcotic effect is inconsequentially different between o2 and n2